[PATCH bpf-next v6 1/2] bpf: enable generic kfuncs for BPF_CGROUP_* programs

Matteo Croce
2024-08-19T16:28:29Z

These kfuncs are enabled even in BPF_PROG_TYPE_TRACING, so they
should be safe also in BPF_CGROUP_* programs.
Since all BPF_CGROUP_* programs share the same hook,
call register_btf_kfunc_id_set() only once.

In enum btf_kfunc_hook, rename BTF_KFUNC_HOOK_CGROUP_SKB to a more
generic BTF_KFUNC_HOOK_CGROUP, since it's used for all the cgroup
related program types.

Signed-off-by: Matteo Croce <teknoraver@meta.com>
---
kernel/bpf/btf.c | 8 ++++++--
kernel/bpf/helpers.c | 1 +
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index bfb0d89ccc8b..b12db397303e 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -212,7 +212,7 @@ enum btf_kfunc_hook {
BTF_KFUNC_HOOK_TRACING,
BTF_KFUNC_HOOK_SYSCALL,
BTF_KFUNC_HOOK_FMODRET,
- BTF_KFUNC_HOOK_CGROUP_SKB,
+ BTF_KFUNC_HOOK_CGROUP,
BTF_KFUNC_HOOK_SCHED_ACT,
BTF_KFUNC_HOOK_SK_SKB,
BTF_KFUNC_HOOK_SOCKET_FILTER,
@@ -8307,8 +8307,12 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
case BPF_PROG_TYPE_SYSCALL:
return BTF_KFUNC_HOOK_SYSCALL;
case BPF_PROG_TYPE_CGROUP_SKB:
+ case BPF_PROG_TYPE_CGROUP_SOCK:
+ case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
- return BTF_KFUNC_HOOK_CGROUP_SKB;
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+ case BPF_PROG_TYPE_CGROUP_SYSCTL:
+ return BTF_KFUNC_HOOK_CGROUP;
case BPF_PROG_TYPE_SCHED_ACT:
return BTF_KFUNC_HOOK_SCHED_ACT;
case BPF_PROG_TYPE_SK_SKB:
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index d02ae323996b..26b9649ab4ce 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -3052,6 +3052,7 @@ static int __init kfunc_init(void)
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &generic_kfunc_set);
+ ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &generic_kfunc_set);
ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
ARRAY_SIZE(generic_dtors),
THIS_MODULE);
--
2.46.0